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Define this
Composition of water
Water as a Solvent
Hard & Soft
Grab bag
100

Define electrolysis

The use of electricity to break a molecule down into smaller units

100

What is the chemical formula of water?

H2O

100

What are 2 types of substances that dissolve in water?

polar and ionic

100

What 2 ions are typically dissolved in hard water?

Calcium and magnesium ions

100

The chemical formula for chalk, calcium carbonate, is CaCO3 .  How many atoms make up one molecule of calcium carbonate?  How many of:

Calcium

Carbon

Oxygen

5 total

1 calcium

1 carbon

3 oxygen

200

Define Polar molecule

A molecule that has slight positive and negative charges due to an imbalance in the way electrons are shared.

200

What links the hydrogen to the oxygen in water?

A (polar covalent) chemical bond

200

What type of substance will dissolve in oil?

non-polar
200

What substance is (typically) added to a water softener?  

Salt.  The process removes calcium and magnesium ions and replaces them with something else, usually sodium ions. 

200

Explain peer review.

When scientists look closely at an experimental procedure and try to find sources of error.

300

Define cohesion

The phenomenon that occurs when individual molecules are so strongly attracted to each other that they tend to stay together, even when exposed to tension.
300

If we collected 4 times as much hydrogen as oxygen in experiment 4.1, what formula might the water appear to be?

H4O

300

If a substance dissolves in a polar solvent, will it also dissolve in a non-polar solvent?  Why or why not?

No.  only non-polar substances dissolve in non-polar solvents 

300

Where do the minerals come from that are in hard water?

They come from the source of where the water is taken, ie the rocks surrounding the water source have metal ions in them.

300

Explain what experimental error is

Reasons why an experiment may not work perfectly

400

Define Hard water

Water that has certain dissolved ions in it - predominately calcium and magnesium ions.

400

Why is water a liquid at room temperature when all other chemically similar substances are gases at room temperature.

Due to the hydrogen bonding 

400

A molecule that has no overall charge because there is not an imbalance in the way electrons are shared is called what?

non-polar 

400

Why is water called a 'near-universal solvent'?

Because it seems water can dissolve nearly anything

400

Can a molecule of oxygen, O2, be polar?  why or why not?

No it cannot because it is composed of 2 identical atoms so the electrons are equally shared.

500

Define Solvent AND Solute

Solvent - a liquid substance capable of dissolving other substances

Solute - a substance that is dissolved in a solvent

500

What is the gas collected at the negative terminal of the battery in experiment 4.1?

hydrogen

500

Explain how soap works.

Soap molecules have both a polar and non-polar end.  The non-polar end attaches to the fat/oil while the polar end dissolves in the water, 'washing' the oils away.
500

Why did we need to add epsom salts to the water in experiment 4.1 if we were only collecting hydrogen and oxygen, which both come from the water (H2O), not the epsom salts?

The epsom salts were required to allow an electric charge through the water so that energy could be supplied to the water molecules to break them apart.

500

Explain surface tension

The phenomenon caused by cohesion in which the surface of a liquid resists tension.